Universal Joint Analysis

Universal Joint Analysis

AIM-To perform a transient structural analysis on a double universal joint with a spring using three different materials: Structural Steel, Stainless Steel and Titanium alloy.

Materials- We will assign three different material to the joint with spring during the analysis, so that we can decide which material is suitable for making the spring to avoid any kind failures. The three different material properties are given in below images-

Stainless steel properties-

Structural steel properties-

Titanium alloy properties-

Comparison of material on the basis of different properties-In this, we have compared the material on the basis of young’s modulus, Poisson’s ratio, yield strength and the ultimate tensile strength which we can see below-

Analysis setup-In this, we analysis the universal joint using spring material as structural steel, stainless steel and titanium alloy. Whereas the material assigned to the other components of universal joint will always be structural steel.

-After assigning the materials eleven joints(10 joints are revolute and 1 joint is fixed) are provided as it was given in the video.

-Now mesh is generated by providing body sizing of 2mm to the spring joint, as we are concerned with stress developed in the spring.

-After the mesh has been generated, analysis settings are changed like setting number of steps to 5, changing weak spring setting to program controlled etc same as it was done in the video. In boundary conditions, we provide rational joint load to the joint which is having no spring.

-Now the analysis is runned.

-Analysis setup will be same for stainless steel and for titanium alloy only the spring joint material is changed.

Results- In this we will see the results that we get for all three materials.

Material	Total Deformation	Equivalent stress	Factor of safety (yield strength criteria)	Factor of safety (ultimate tensile strength criteria)
Structual steel
Stainless steel
Titanium alloy

Discussion on the basis of results-

-Total deformation- It will be same for all the materials, as the same amount of rotation is given in all the cases.

-Equivalent stress- It has been observed that the stress value is very in case of titanium alloy as compare to the other materials. This is because titanium alloy has very low value of young’s modulus which is 96000 Mpa as compare to the other material. Young\'s modulus measures the resistance of a material to elastic (recoverable) deformation under load. A stiff material has a high young\'s modulus and changes its shape only slightly under elastic loads (e.g. diamond). A flexible material has a low Young\'s modulus and changes its shape considerably (e.g. rubbers). So, structural steel and the stainless steel doesn’t change there shape that much as the titanium alloy can and thus result in higher stress value.

-FOS (yield strength criteria) - As we clearly know, that yield strength of titanium alloy is maximum as compare to the other two materials. Therefore, the value of FOS (yield strength criteria) is maximum for the titanium alloy. Whereas the structural steel and the stainless-steel spring fails due to very low yield strength.

-FOS (ultimate tensile strength criteria)- In this case also, the value of FOS (Ultimate tensile strength criteria) is maximum for the titanium alloy. As titanium alloy have maximum value of ultimate tensile strength as compare to the other materials.

Suggestion-On the basis of above results, we should select the titanium alloy as material for the spring rather than the structural steel and stainless steel. Because the stainless steel and structural steel both will get fail when they are put in real work conditions. Titanium alloy have another advantage of less weight as it has low density value as compare to the other materials. But on the other hand, titanium is quite expensive.